| 摘要 |
<P>PROBLEM TO BE SOLVED: To sufficiently improve an NF characteristic when an input high frequency signal has a low level, and sufficiently improve a distortion characteristic when the high frequency signal has a high level. <P>SOLUTION: A bias control section 11 comprises a resistance R9 connected between Vcc and a coil L2 (load means) connected to a collector of TR1, and a series circuit of TR3 turned on/off in response to a control voltage Vgc and a resistance R8, connected in parallel with the resistance R9. When an input signal has a low level, the control voltage Vgc turns off TR2, TR3, and a resultantly reduced bias to TR1 leads to an improved NF characteristic. When the input signal has a high level, the control voltage Vgc turns on TR2, TR3, and a resultantly increased bias to TR1 leads to an improved distortion characteristic. <P>COPYRIGHT: (C)2013,JPO&INPIT |
